A 26-week gestation infant at one week postnatal age should be in an incubator environment with relative humidity at approximately which percent?

• A. 50%
• B. 70%
• C. 90%
• D. 60%

Answer: (B)

Maintaining a humidified incubator helps prevent excessive water loss from an extremely premature infant’s skin and mucous membranes. At 26 weeks, the skin is very thin and TEWL (transepidermal water loss) is high, so a higher humidity environment helps preserve body fluids and support stable thermoregulation.

About 70% relative humidity is used in this scenario because it provides enough moisture to reduce dehydration without causing excessive condensation or overheating—the risks increase if humidity is too high or too low. As the infant’s skin matures and fluid balance stabilizes, humidity can be gradually reduced.

So the target is an approximate 70% humidity level in this very preterm infant during the first week after birth.